New solar plane takes maiden voyage

A plane designed to fly day and night using solar power has successfully taken its first maiden flight.

The Solar Impulse HB-SIA soared into the air for its first flight early Wednesday from its home in Switzerland. After a smooth takeoff, the plane climbed to an altitude of 1,200 meters (3,937 feet or three-quarters of a mile) and stayed aloft for a total of 87 minutes. Pilot Markus Scherdel used the flight to run the Impulse through different exercises and maneuvers to see how it would handle itself.

As thousands of spectators gazed skyward, Scherdel worked the controls to take the plane on a series of intricate turns and then steered the Impulse to simulate its approach and landing phases. Though piloting an aircraft so big and light is considered both difficult and risky, Scherdel's maiden flight proved a success from takeoff to landing.

"This first flight was for me a very intense moment," said Scherdel as he stepped down from the aircraft following the flight. "The HB-SIA behaved just as the flight simulator told us. Despite its immense size and feather weight, the aircraft's controllability matches our expectations."

The Solar Impulse HB-SIA is designed to fly without the need for fuel. Though its wingspan is as wide as that of a Boeing 747, the plane weighs only around 1.7 tons. The 12,000 solar panels on its wing collect energy from the sun to drive its four electric motors and charge the plane's lithium polymer batteries, allowing it to fly at night.

Though the plane will ultimately use solar power for an upcoming flight this year, the maiden flight relied solely on the batteries, which were powered up beforehand in the hangar. The Solar Impulse's first official flight followed a successful test flight in December, which was labeled more of a "flea hop" since the plane only traveled 3.2 feet off the ground for a distance of 1,148 feet.

Wednesday's flight was the first to see how the plane would fare at a high altitude over a longer duration. It was also considered the riskiest phase of the project by Solar Impulse CEO and co-founder Andre Borschberg as the 87-minute journey represented the culmination of seven years of research and testing. Borschberg said that the success of the maiden flight brought about a greater sense of serenity to move forward to the next phase.

Next on the plane's itinerary will be further test flights, each one increasing the distance and duration that it stays in the air. The first day-and-night flight is scheduled for this summer to see if the Impulse can remain aloft for 36 hours operating on just solar power and batteries. Grander ambitions lie ahead for 2012 with a flight that will navigate around the world in five hops over the course of four to six days.

The Solar Impulse reached an altitude of 3,937 feet on its 87-minute voyage.
Solar Impulse/Stephane Gros

"We still have a long way to go until the night flights and an even longer way before flying round the world, but today, thanks to the extraordinary work of an entire team, an essential step towards achieving our vision has been taken," said Solar Impulse Chairman and initiator Bertrand Piccard, in a statement. "Our future depends on our ability to convert rapidly to the use of renewable energies. Solar Impulse is intended to demonstrate what can be done already today by using these energies and applying new technologies that can save natural resources."

See also our slide show from the Solar Impulse's very modest "flea hop" test flight in December: